EP0149250B1 - Distribution mounting for the end parts of glassfibre cables - Google Patents

Abstract

1. A distribution rack for the ends of glass fibre cables for apportioning the bundles of fibres, or the individual glass fibres of a glass fibre cable, as the case may be, to one of a number of glass fibre couplings corresponding to the number of glass fibres, which, for measuring purposes, are separately releasable and individually accessible in respect of each glass fibre, characterised in that the rack (1) is subdivided as regards its height into at least two sections, namely a reception region (2), preferably in the form of one or more magazines (3) to receive the spliced connections between the individual glass fibres of the cable and first flexible connection leads (4) (so-called pigtails), and a region (5) for the reception of the glass fibre couplings ; and that the free ends of the first connection leads (7) opening into the couplings are held near their ends in clamps (8) and at their ends carry the couplings free for connection with a further secondary connection lead (9) in each case leading to the evaluation output rack (5).

Description

The present invention relates to a distribution frame for fiber optic cable ends. Such racks are needed similar to cable end racks of conventional communication cables, the ends, i.e. the individual glass fibers, which form a glass fiber cable in bundles, to the individual receiving or demodulating devices.

The peculiarity of such a distribution frame for fiber optic cable ends compared to other distribution frames or marshalling racks for conventional electrical cables is that information about the individual cable fibers for measurement and monitoring purposes is not possible, as is the case with electrical cables, by means of a parallel connection or inductive coupling, but that in any case the fiber optic path must be separated in order to send the flow of information through the fiber to the measuring or monitoring device.

For this purpose, fiber optic couplings have become known, which the two ends of two fiber optic cables, z. B. also from one end of the cable and a connecting line in the form of a so-called pigtail. These fiber-optic couplings, which are manufactured with very high manufacturing costs, should therefore only be used in a distribution frame where it is actually necessary to cut the light path.

Another peculiarity of such a frame is that the individual fiber optic lines, although their flexibility would allow them, should be bent as little as possible, since in contrast to electrical conductors, the attenuation in the cable wires depends on the laying or the individual radii of curvature. So while with a distribution frame for the core of an electrical cable, it is only necessary to ensure that the individual lines are not laid in the form of a coil, as this would result in excessive inductive resistance, an arrangement must be made with a distribution frame for fiber optic cable ends, despite which the arrangement of couplings guarantees the most straightforward routing of the information flow from the cable end to other connecting lines.

Conversely, there is not an arbitrarily large space available for such distribution racks, whereby it must be taken into account that generally about 10 glass fibers are combined into a bundle and again 7-10 bundles into a cable and are accordingly distributed in one or at least in a few racks and with Connection lines must be coupled.

The object of the invention is therefore to provide a distribution frame for fiber optic cable ends for dividing the fiber bundles or the individual glass fibers of a fiber optic cable, in which in addition to the connection of the cable ends with connecting lines, fiber optic couplings can be easily accessible in a quantity corresponding to the number of glass fibers , in which the individual fiber optic couplings are accessible without impairing the other fiber optic couplings, a cable routing is guaranteed which manages with very few bends with a relatively large radius despite a small space requirement and which guarantees easy handling.

This object is achieved in a distribution frame for fiber optic cable ends by realizing the features of claim 1.

In the distribution frame for fiber optic cable ends according to the invention, the frame is divided over the height into at least two sections, namely a receiving area for receiving the splice connections between the individual glass fibers of the cable and first flexible connecting lines and in an area for receiving the fiber optic couplings, the Couplings are kept free from the ends of the first flexible connecting lines in the form of so-called pigtails in that they are held in a clamp even near the end which is inserted into the coupling, and each individual fiber in its own clamp.

The cables are routed in such a way that, for example, the glass fiber bundles are first inserted into the frame from below or from above, and the individual fibers are spliced (welded) to one end of the first connecting lines in the lower region, and the splice connection in this region is preferably stored in magazines will. From these magazines, i.e. So from the lower receiving area, the first connection lines are gem. an advantageous embodiment of the invention on one side of the distributor frame up in the area of the glass fiber coupling. In this area, the individual terminals for holding the free ends of the first connecting lines, through which the individual ends of the first connecting lines are inserted, are provided one above the other, to the extent that there is only a short free end on the rear of the terminals, onto which the couplings are inserted with an insertion side. The short free ends of the individual glass fibers are so stable that the couplings are carried freely.

The terminals themselves are arranged one behind the other, as seen from the bottom up, with a slightly inclined terminal opening in the direction of the information flow going upwards.

This measure ensures that a clamp must first be provided for each possible cable end in the manufacture and equipment of the frame, but that only couplings in one frame are required in such a number as actually glass fiber ends are later pulled into the frame.

Furthermore, this arrangement guarantees that the first connecting lines leading from the bottom up on one side of the frame need only be slightly curved in order to be able to be inserted into the individual terminals, and that the second connecting lines then connecting to the couplings, also so-called. Pigtails, only have to have a corresponding curvature in the opposite direction, in order to then be led out of the frame to the actual end frame.

According to an advantageous embodiment, it is advisable to use simple push-button clamps as clamps, the clamp surfaces preferably being of polygonal shape in order to secure the glass fibers introduced in detail with their sheathing against twisting even with only slight pressure. This is important because couplings are placed on the free ends of the connection lines that look through the terminals, on which occasionally a certain torque is exerted when loosening and connecting, but this should not lead to a twisting of the glass fiber connection lines and may.

Further features of a distribution frame according to the invention and the advantages that are given in the implementation are explained below in connection with the accompanying drawing.

• Fig. 1 in perspektivischer und teilweise aufgeschnittener Form den Grundaufbau eines Verteilergestells nach der Erfindung mit einigen Einzelheiten zur pauschalen Erläuterung,
• Fig. 2 eine entsprechende Frontansicht des in Fig. 1 dargestellten Verteilergestells,
• Fign. 3 - 5 den konstruktiven Aufbau der Verteilerplatten für die einzelnen Klemmen für die Enden der Anschlußleitungen und
• Fign. 6 + 7 den Prinzipaufbau einer Glasfaserklemme, wie sie für die Zwecke der Erfindung in einem Verteilergestell in großer Stückzahl verwendet werden können.

The drawing shows:

• 1 is a perspective and partially cut-open form of the basic structure of a distribution frame according to the invention with some details for a general explanation,
• 2 shows a corresponding front view of the distributor frame shown in FIG. 1,
• Fig. 3 - 5 the structural design of the distributor plates for the individual terminals for the ends of the connecting lines and
• Fig. 6 + 7 the basic structure of a glass fiber clamp, as they can be used in large numbers for the purposes of the invention in a distribution frame.

First, with the help of FIGS. 1 and 2 explain the basic structure of a distribution frame for fiber optic cable ends with some details and design options.

In these figures is generally designated 1 the entire frame, which has a receiving area 2 for receiving the splice connections in the lower part. A glass fiber cable 10 is divided at the entrance to the distribution frame 1 into corresponding fiber bundles 11, which are initially held together by an elastic hose (not shown). In order to relieve the cable itself of any train, a holder 12 is provided. The electrical conductors 13, which are generally carried in a glass fiber cable for monitoring and measuring purposes, are led out of the bundle behind this holder.

The glass fiber bundles 11 are laterally guided all the way down in the frame, where they are guided into bundles for bundles 3 in bundles in bundles 3. In these magazines 3, which are removable per se and which are each equipped with the number of fibers in a bundle, for example with 12 pockets, are spliced with first connecting lines 7, i.e. The welds between the cable end and the first connecting lines 7 are accommodated in the magazines. In order to facilitate welding, the magazines can be removed individually, and accordingly a large loop of the cable end 11 and the first connecting lines 7 must be provided.

The actual coupling insert 5 is provided above the receiving area for the splice connections. In this space, one above the other, which can only be hinted at in the figure for reasons of clarity, terminals 8 are provided, into which the first connecting lines are led, i.e. through which the free ends of the first connecting lines are inserted and clamped. The individual glass fiber couplings 6 are plugged into the rear of the terminals 8 and the free ends of second connecting lines 9 then open on the side of the couplings 6 facing away from the terminals 8.

Above this coupling insert with, for example, 30 terminals to be arranged one above the other and possibly also couplings, a soldering insert is then provided in the exemplary embodiment shown with a prewired socket field 13, a nameplate 14, soldering lugs 15 and a holder 16 for the copper lines 6. These links serve for an additional Monitoring and data exchange, via the copper lines 13, which are carried, for example, in the glass fiber cable 10, as mentioned. These devices are not the subject of the present invention.

To relieve the individual connecting lines are at a suitable point, for. B. top right at 17, additional strain relief members, in which the individual glass fiber connection lines or even bundles thereof can be clamped and held.

The final wiring of such a distribution frame is done by first removing the sheath from the optical fiber cable over a length corresponding to the height of the frame plus the length corresponding to the guide in the receiving area for the splice connections. In the upper area of curvature, a flexible tube is then pushed over the fiber bundles opened in this way and with the help of the flexible tube, the tube and fiber bundle unit is attached to the holder for the flexible hose 12, a cable tie. The individual fiber bundles are then laid down in the space provided in the left area and in turn secured to a holder for the fiber bundles 18. The ends of the fiber bundles are then exposed and guided into the individual magazines 3 and, if necessary, held over further cable ties 19 when they enter these magazines.

Then the individual first flexible connecting lines 7 are laid, care being taken to ensure that the end remaining in the individual splice magazines is approximately the same length for all connections, so that, depending on the height of the terminal 8 provided for the individual connecting line, different lengths for the Connection lines must be provided.

The free ends of this first flexible connecting line are inserted into the corresponding terminals 8 and initially held there.

Now these first flexible connecting lines 7 can be spliced to the ends of the optical fibers by removing the individual magazines 3 and can be stored in the individual pockets to be provided in the magazines, taking into account a minimum radius.

Then the second flexible connecting lines 9 are then introduced from above and are guided in the appropriate length to the individual couplings 6 placed on free ends of the first flexible connecting lines 7.

The connecting lines 9 emerging at the top are held together in a holder 17 and then routed together to correspondingly provided cable ducts.

The copper wires 13 are laid to the upper soldering insert in a manner known per se.

Using the figures 3-5, the structural design of the holding plates for the terminals 8, into which the free ends of the first flexible connecting lines 4 are to be inserted, is explained below.

According to the embodiment according to FIGS. 3-5, these clamps 8 are fastened to the front of a holding plate 31 inserted into the frame near the center. For this purpose, the holding plate 31 is provided on the side adjacent to the rear wall of the frame with a bent foot 32, via which the holding plate is permanently fixed, for example by spot welding points 33. The front edge of the holding plate 31 is cut in at the side and the tabs 34 thus formed are seen in the plan view in FIG. 2, angled to the right at an angle, so that they are slightly inclined with respect to the vertical extent of the frame.

The clamps 8 are then attached to these individual tabs 34 in such a way that the through openings for the free ends of the first flexible connecting lines are inclined slightly upward, as in FIGS. 1 and 2 also indicated.

For the sake of clarity, only one clamp is drawn in FIG. 4 as a dashed rectangle on the second tab 34 of the holding part 31, the passage opening for the free end of the connecting line being indicated.

For the structural design, it is advisable not to endure the holding plate as a unit for the entire receiving space for the couplings, but in several pieces, for example by assigning about 10 clamps to each individual holding plate.

For this training, it is initially irrelevant how the clamps to be fastened on the retaining tabs 34 are designed. It is crucial that the terminals take up relatively little space and hold the free end of a connecting cable in such a way that it is not crimped but is secured against twisting.

An embodiment with a basic construction for such a clamp is shown in FIGS. 6 and 7 are shown schematically. The terminal 8 shown in FIG. 6 in a side view and in FIG. 7 in a top view of the actuation push button has an essentially rectangular base body 61 with an approximately square cross section, in which an opening 62 is provided for pushing through the free end of a connecting line. In the body 61, the opening 65 present in this pressure piece is moved against the force of a spring 63 by means of finger pressure on a pressure piece 64 until both openings are aligned. In this state, the free end of an optical fiber line can then be inserted. The glass fiber is then clamped in by the force of the spring 63 when the finger is removed, and a good securing of the glass fiber against rotation is guaranteed by shaping the opening 65 with a trapezoidal cross section.

According to the invention, a coupling piece is to be placed directly on the end of the light guide guided through a terminal 8, which must also be released again and again in practical operation. For this reason, according to In an advantageous development of the inventive concept, each clamp 8 is assigned a protective sleeve 66 on a flexible holding cord which is always plugged onto a free glass fiber end when one end is released via the coupling. This is particularly important during assembly if initially only the ends of all flexible connecting lines are plugged in, while by no means all lines have yet to be fully occupied and continued via couplings.

Such protective sleeves are well known in connection with glass fiber technology and are not the subject of the present invention. It is only essential for the present invention that they are provided in a fixed location where they are constantly required in later operation.

The present invention has been described in great detail in the interests of traceability by those skilled in the art. The cable routing is essential and of fundamental importance for the reasons mentioned in the introduction. The construction of clamps, the arrangement of the clamps, if necessary, in several parallel planes side by side or one behind the other, as well as the design and arrangement of cable ties, holders for individual cables, etc. is within the scope of professional skill and can be implemented on a case-by-case basis. In particular, it can be advantageous to arrange parallel qi31tepl 'itten slidably in their plate plane relative to each other and to provide them with staggered holding tabs so that when mounting on couplings of a holding plate, this can be pulled out a little and / or pushed back . It is essential that, in the space specified by the postal administrations, the present invention enables for the first time a line routing with access to all individual couplings, in which the conditions imposed on the fiber optic technology can be met.

Claims (9)

1. A distribution rack for the ends of glass fibre cables for apportioning the bundles of fibres, or the individual glass fibres of a glass fibre cable, as the case may be, to one of a number of glass fibre couplings corresponding to the number of glass fibres, which, for measuring purposes, are separately releasable and individually accessible in respect of each glass fibre, characterised in that the rack (1) is subdivided as regards its height into at least two sections, namely a reception region (2), preferably in the form of one or more magazines (3) to receive the spliced connections between the individual glass fibres of the cable and first flexible connection leads (4) (so-called pigtails), and a region (5) for the reception of the glass fibre couplings; and that the free ends of the first connection leads (7) opening into the couplings are held near their ends in clamps (8) and at their ends carry the couplings free for connection with a further secondary connection lead (9) in each case leading to the evaluation output rack (5).

2. A distribution rack as claimed in Claim 1, characterised in that the individual connectors (8) viewed in an upwards direction are arranged one behind another with a clamping opening (62) inclined in this direction.

3. A distribution rack as claimed in Claim 1 and 2, characterised in that the clamps are provided in the form of spring-loaded press-button clamps (8).

4. A distribution rack as claimed in Claim 3, characterised in that the clamping surfaces of the clamps are of polygonal shape to prevent twisting of the ends of the connection leads in the couplings.

5. A distribution rack as claimed in Claims 1 to 4, characterised in that, viewed across the width of the rack, the clamps are arranged eccentrically in such a way that the couplings which are to be brought to the ends of the connecting leads which are led through the clamps come to lie near the middle of the rack.

6. A distribution rack as claimed in one of the previous Claims, characterised in that for the insertion of the cable end, a lateral shaft is provided for leading the cable ends inserted from above and divided up into fibre bundles, downwardly to the reception region (2).

7. A distribution rack as claimed in one of the previous Claims, characterised in that relief holders are provided in the region of the cable entry points and of the connection lead exit points, as well as in the region of tight turns.

8. A distribution rack as claimed in Claim 5, characterised in that to each clamp (8) there is permanently allotted a protection sleeve known per se for slipping on to an end of a glass fibre freed from the protective sheath.

9. A distribution rack as claimed in Claim 1 to 5, characterised in that the clamps (8) are distributed on to a plurality of supporting plates arranged parallel to one another and movable with respect to one another in the plane of the plates, the holding lugs (34) of which are arranged to be staggered with respect to one another.

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